To cover reproach with reproach is to lay mud upon mud.

Explanation

(English-origin maxim.) Answering defamation with defamation only compounds the wrong — a party who retaliates with his own reproachful language forfeits the clean hands needed to seek equitable relief.

Where this applies

• A defendant in a defamation suit argues that the plaintiff defamed him first, but the court rules his retaliatory insults forfeit his right to equitable relief — answering mud with mud leaves both parties dirty.
• A business owner responds to a competitor's false advertising by publishing his own lies about the competitor; the court denies his claim for an injunction because he has unclean hands.
• An employee sues for workplace harassment but is found to have sent equally vile messages in return; the court notes that retaliating with reproach does not cure the original wrong.